Hot-air heater with selective indirect draft



April 20, 1948.

F. B. GAMBLIN Filed Oct. 19, 1944 HOT AIR HEATER WITH SELECTIVE INDIRECTDRAFT 4 SheetsSheet 1 DTIUBTTDT 1 B GaTnYfli'n April 20, 1948.

F. B. EGAMBLIN HOT AIR HEATER WITH SELECTIVE INDIRECT DRAFT Filed Oct.'19, 1944 4 Sheets-Sheet 2 April 20, 1948. F. B. GAMBLIN 2,439,972

HOT AIR HEATER WITH SELECTIVE INDIRECT DRAFT Filed Oct. 19, 1944ISheets-Sheg 3 68 I 6? :w 50 40 o 0 o O 0 66 6 41 3: a0 1 v '2 1 g M n A1 a9 184 f M I mmmm 2 76 75 Z8 4 50 +5 56 *2!) 26 5% 5 2111M 3.! ,u- -27W 4' {/lr T" b8 60 b9 p il 1948' FQB. GAMBLIN 2,439,972

HOT AIR HEATER WITH SELECTIVE INDIRECT DRAFT I Filed Oct. 19, 1944 4Sheets-Sheet .4

I'M/m;

W 4 7 m .a

La v a M Patented Apr. 20, 1948 STATES PATENT OFFICE HOT-AIR HEATER WrrnSELECTIVE INDIRECT DRAFT Fay. B. Gamblin, Smithers, B itish Golumbia,

Ganad Application-October 19, 1944', Serial-'No.'5'59,394f

10 Claims.

invention relates to improvements in heating systems of the kindcomprising stoves. and

Aiurtherobject of the invention is to provide a heating-system that canbe-readily controlled, and; one which has flexibility of heatregulation.

AStllr further object of the invention is to supply-- a heating systemin which foul air is drawn off a room and replaced by fresh air heatedto a desirable temperature.

Having described the major object of the invention; subsidiary objectsand advantages will appear as the invention is fully described in thefollowing specification of which the accompanyingdrawings form a part.

In the drawings;

Fig; 1 is a side elevation of the inventionas a stove.

Fig; 2 isalongitudinal, section thereof through the-casing of theradiator. Inthis view a hinged cowling'of a casing is shown raised topermit access to the firebox lid for fueling purposes.

Fig. 3 is a vertical section through the stove but: showing the cowlinglowered, as in Fig. 1.

Fig. 4' is a section taken on line 4-4 of, Fig. 2.

Fig; 5 is a section on line 55 of Fig. 3..

Fig. 6. is a perspective detail of the ventilator by which foul. air isdrawn off a room. from. the floor line.

Fig. '7 is a detail of. the combined damper and deflector which isconnected in tandem to a slide plate inthe ventilator.

Fig. 8 is a detail of the clean-out door at. the. hacker the stove.

Fig. 9 is a cross section, of the cowling taken on. line 9-9. of Fig. 2and depicting a device for securing it in a raised position.

Fig. 10 is a tractional bottom. plan. of the stove showing the feetupon. which it stands.

Fig. 11'' is. a sectional plan takenon line I I--Hv of. Fig. 3illustrating. the grate construction in the firebox.

Fig. 12 is a cross section on line I l-i2 of Fig. 11 showing. thearrangement of; the shaker bars of the grate.

Fig. 13 is. a perspective detail of the shaker bars of. the, grate.

Fig; Hisa perspective detail of the-rocker bar of thegrate.

Fig. 1.5 is a fractional front. view of the stove depicting the casingbroken. away to show the ashpit door to better advantage.

Fig. 16 is a fractional section on line Iii-4B.

of Fig. 1. showing the ashepitdoor' and, the outside door in. the.casing. that surrounds the fire bDX;

Fig, L7 is a front view or the lower portion of the stove depicting theoutside door that renders. the ash-pit. door accessible.

Fig. 18 isa. general schematic view of the invention, as a furnacewhich. is shown located inabasement of, abufldinawith a duct for dawingin fresh air and a duct for drawing off foul air.

Fig. 19 is a plan view of the register in the fresh air nletpipe shownin. Fig. 1.8.

Fig. Ellis; a perspectivedetail ofthe; directional damper shown belowthe register in the fresh air pipeof- Fig. 18.

Like numerals of: reference-denote similarpar-ts in each figure of thedrawings.

In describing my heating plant I shall at first refer toIFigs. 1. to 17.inclusive in whichthere-is shown; a heater of the: stove type. Theheater comprises a firebox 21, the upper part of which forms acombustion. chamber defined in part by the top wall 22. The front wallofthe firebox is preferably rounded as at 23* and merged into the parallelside walls 24: which extend to the rear wall: 2-5; The grate is; denotedas a whole by the character A.

The upright walls of the firebox are integral with or secured to a baseor-bottom wall.- Z-BWhich extends outwardly and rearwardly thereof, asshown, and is supported upon legs 21. The

grate A is disposed above the bottomv Wall 26" to provide an ash pit 28.The legs, four in numher; are shown as U-shapedmembers having lugs 29extending outwardly from the upper ends by which they are bolted to thebottom wall 25.-

The: legs are curvedin plan to conform to the curvature of they endsofsaid bottom wallv as will best be seen from. an inspection of Fig. 10.

The front end of the top of the firebox is provided with a feed door 30for fueling purposes, which, is in the form of a lid hinged at its rearto swing upwardly. I arrange the lid to slope forwardly in its closedposition so that when raised itwill facilitate replenishing of fuel,especially comparatively longpieces of wood which can be easily: insertd lathe. slopin op nin ncovered by the lid. The lid is supplied with aforwardly projecting handle 3| which terminates in a grip portionfashioned of coiled wire as is common to the art.

An important feature of construction of the heater resides in the novelarrangement of a radiator for heating air by means of the products ofcombustion. The structure comprises a first vertical tube 32 at the rearof the firebox and communicating therewith at the top thereof by meansof a duct 33, and a second vertical tube 34 communicating with saidfirst tube by a bottom duct 35 and a top duct 36. These tubes are heatexchangers through which the gases may be diverted in their passage tothe smoke pipe 31 which leads ed the top of the second tube 34. In thediverted travel of said gases they '4, a radial slot 55. A hole isprovided in the tandem rod for selective engagement with any one ofthese pins that gives the desired throw and the engagement is maintainedas by a leaf spring 56. According to this construction it will bemanifest that by lengthening the radius of operation of the lowerendofthe tandem rod a shorter throw will be communicated to the checkdamper 44 in closing the upper damper 4| with the result that the roomtemperature will be increased.

The check damper 44 controls a port 51 in .the bottom wall 26, which isencased by a venflow downwardly through the first tube and upwardlythrough the second tube as indicated by. the arrows in Fig. 3. The firsttube is spaced from the firebox to provide an intervening passage 38 forcirculation of air, and the second tube is spaced to similarly providean'air passage 39. The ends of the tubes are closed off by prolongationsof the walls 22 and 25 of the firebox save for the connection of thesmoke pipe, for which purpose the top wall extension is supplied with aflanged collar 40 riveted thereto to seat the lowermost length of stovepiping.

The duct 36 is supplied with a butterfly damper 4| mounted on ahorizontal axis which extends outwardly to one side of the heater and isfitted with a lever having arms 42 and 43. The arm 42 terminates in arip member suitable for hand operation of the lever. The arm 43 formsapart of a mechanical device for actuating the lever, which will bedescribed later. The damper regulates the flow of gases through the duct36 and in its fully open position the gases wholly travel directly tothe smoke pipe. In the closed position of the damper the gases arediverted downwardly through the tube 32 to the duct 35 thence upwardlythrough the tube 34 to the smoke pipe. Accordingly the air surroundingthe tubes is heated thereby.

At the lower end of the tube 34 I provide a combined damper anddeflector 44 hingedly disposed at the outlet side of the duct 35 bymeans of a shaft 45 controlled by a lever terminating in a handgrip 41for manual operation. The combined damper and deflector serves to divertgases upwardly from the duct 35 and also acts as a check and mixingplate as will later be explained.

Desirably its shaft 45 is journalled in arms 48 carried by a cover plate49 of a clean-out opening 5|] in the tube 34. The arrangement is suchthat the combined damper and deflector is removable as a unit with thecover plate 49 so that the radiator tubes may more easily be cleaned ofsoot, etc.

The combined damper and deflector and the cover plate 49 are detailed inFig. '7. The lever 46 is connected by a tandem rod 5| to the leverarm 42aforesaid. The upper end of the tandem rod has a slot 52 in which a pin53 on the arm 42 is free to slide so as to provide an attachment bywhich lost motion takes place in one direction of movement. By thistandem rod connection the combined damper and deflector 44 will beautomatically raised to an open deflecting position-- as shown in Fig.3-should it not previously have been set in such position. As will bestbe seen from an'inspectio-n of Fig. '7, the lower end of the tandem rodis attached to the lever 46 by a device that permits of'adjustment ofthe-throw. This consists of a lengthwise series of pins '54 withifi.tilator 58 in the form of a box, detailed in Fig. 6, which depends tothe fioor of the room. One of the sides of the ventilator is aperturedat the bottom to; furnish a port 59 for admission of foul. air drawn offthe room. The air thus inducted mixes with the gases and is conductedthrough the tube 34 to the smoke pipe. The port 59 is controlled by aslide plate or shutter 35 vertically guided as by a pin and slotconnection indicated at 6|. The slide plate is actuated by a tandem rodor link 62 which is pivcted thereto at one end and likewise connected atits other end to the damper 44. 'By this arrangement the slide plate isautomatically controlled by the check damper 44, and it will be gatheredthat when this damper is thrown to a horizontal position in which itcloses the port 57 the port 59 is closed concurrently by the slideplate. The ventilating device is an im ortant feature of the inventionin that it functions to exhaust from a room the cold foul air at floorlevel when the port 53 is opened. The ventilator should be disposedimmediately adjacent to the floor to secure best results and for thisreason it is proposed that in the manufacture of-the heater theventilator shall be madein difierent depths'so that one of the requireddepth may be used according to whether or not a floor mat is employed.To this end the ventilator is detachably connected to the wall 23 as bybolting its flange 63. thereto, which renders it interchangeable.

. The firebox 2| and the heat exchanger tubes 32 and 34 at the rearthereof are encompassed by a casing 64 which is spaced therefrom toprovide an air chamber 65 that also extends above the top wall 22. Thecasing is closed by a hood 63 substantially formed by a cowling Elextending forwardly from a point near the rear where it is hinged as at68 to swing upwardly so that it may be raised as shown in Fig. 2 to gainaccess to the lid 30. The cowling has a side flange 69 fitting aroundthe wall of the casing, which is apertured at intervals as at 10. Ahandle 1| is carried at the front for raising the cowling. The hood islikewise apertured as at 72. The casing is attached to the bottom wall26 in suitable manner and otherwise supported as circumstances ofmanufacture dictate. Apertures as at l3 are supplied in the sides of thecasing immediately above the bottom wall 28 to constitute cold airinlets, the air admitted thereby being heated bythe firebox and the heatexchanger to the rear thereof and rising to the outlet apertures Ill and12 for circulation about the room. This construction provides a maximumof hot air circulation and an optimum of heating efficiency.

The cowling will carry a suitable catch 14- best shown in Fig. 9-bywhich the lid 3|] may be held in an open position when the cowling israised. This enables the person tending the avg-ra ars:

stove to: use both. handsfiin. order" to lay large pieces of wood on.the fire; in. orderly manner i n repl'enishingf the'fuel. The catch may;be: of a form to slide transversely baclc and: forth of the handle 3! toengage: and" disengage the. same. A cleant-out door '05: wili; provided.in the back ofth'e casing in register with the clean-out plate @91aforesaid for access thereto: This door may beheld in place by springcatches it riveted. i'i'L place:best discernible: in. Fig; ii.

The cowling d'lr is-ifurriished with a. mechanical connection to: thedamper. M so. that as it is raised it. will. open thisv damper;automatically to: draw up the fireor' to permit residual smoke; topassdirectly to! the. smoke? pipe: 31 at. the time of refueling; Themechanical connection consists of a link; H pivoted at T8 to' a. side.of the cowli'ng. and. provided: with a lengthwise slot T9 in which thelever arm- 43: is slidably' pinned; The slot is enablesthe lever. tooperate inde-- pendently of the: raising of. the. cowlingr' in. the useof the handle arm 42-.

Now, referring back to; the grate A; this: is of: a novel constructioncomprising two sets of transverse shaker. bars-- as at 8.9:, haying;their inner ends inter-fitted: in: staggered formation and notched;inwardly of their bottom faces asat al Thenotches are-substantiallyV'-shapedand each isenlarged circularly at its vertex as at 82 to?receive a rounded: key member 83- of a rocker bar Bi l; The key member.loosely engages the said: notches and is integrated with the; rockerTQdLOI' bar by a web 85: Bar 84- is; turnably mounted in the firebox:and: projects forwardly through the casing 64 to receive a detachabl'e.shaker crank Mi. The. outer ends of saidshakcr bars 8E!- rest uponbenches 6 and: are: free toslide endwise. Theshaker bars ofeach: set arerigidly united. in spaced relation by a tie rod 88* carrying distancepieces: 38- by which the shaker harsare spaced: Theshaker barsreciprocate when the rocker bar 84 is oscillated by the. crank,. themovement being. limited by the angle of the \li-shaped: notches iii: to:about a quarter.- turn; This shaker action is smooth and. operates tothoroughly sift out. ashes with.- out unduly disturbing the fire;

The ash pit in is, fitted with a: swing door 90' at the front of the:firebox' which. is curved in conformity to-the curvature thereof. Thisdoor has: draft induction slots controlled by a rotary shutter 9icentrally pivoted and supplied with knob by which it can be" manuallyturned. Saint rotary shutter; is constructed with taperingslots 92 forco-acting witlr the said induction: slots of the door. The: taper of theslots 92. enables a. fine adjustment. to be had in regulating thedraftwhich isnecessary on account of" thevhighl'yefficient heating?apparatus ofthe invention; A door" 93: in the front of the casing: 64-renders the ash: pit door accessible and isprovided with a circular handhole: 9% by which: access may be. hadto the rotary shutter without the:ncciessity of; opening the door. 3%; in regulating the draft-.

Now; adverting to. Fig. 13' it will be seen that I have herein shown anembodiment. of my invention: as a; hot air furnace, the construction.

within the casing of which is the same as that. above recounted, except.that the. ventilator is dis-- pensedwith and in its place: there is:provided: a; pipe 9.5 for foul air. pipe is sunk in the foundation; uponwhich the furnace rests and has; an; elbowconnection 93- with. the baseof thefunnace in register with the: port 51. which is con;-

trolled by the: combined: damper and. deflector 44: aforesaid. This:pipe: slopes upwardly and outwardly' from. the furnace. to the floorand. at. floor level is" provided. with a register 91 for admitting.foul air draw/n; off the. room and: mixed. with; the products; ofcombustion for conduction to: the smoke pipe.

A: furthen variation: of the furnace; structure is thatthe: casing;indicated at 913;. does not: have at cowling: over the firebozclidg.denotedtats'fi. Thelid-98 exposed: and connected: by a slotted link Hillto: the: arm 43 for operating; the damper: 41? in the: manner describedin. connection with the link 11 aforesaid. The casing is; supplied withhot. air piping: l0] for delivery: of heated air to roomsaboive thebasementiin' which theefumace is installed; the fi'oor. abovethezhasement beingindiieaten at Hi2 and. one of the outside walls of thebuilding; being shown at I113;

As a further feature of the furnacev structure; the casing: thereof; isprovided with. a. pipe Hi4: communicating: with; the radiator chamber:m5- near the: base" and; extending upwardlyto the. ceiling andoutwardly'through' the wall I 03 where. it terminates. in a. downturnedtelbow Hi6. suitably" screened as at i011 Pipe I'M serves for the.induction of. fresh air intothe heating. compartment or the: furnace:and the ingress is' controlled by a: direction: damper: 181; Above thisdamper thepipe issupplied' with a register H19 which is:disposediwithirr. the building and. raised: above: the floor [021.This-register may have aagrating formed of slats: united by tie rodsand: removabl y sup' ported;

The. directional: damper I08. 1 plate hinged: at Hi] to: swing.transverselybeneath the: register "id in; a manner to open and; closethe same and also; to open: and close the fresh air inlet. Thedirectional damper is actuated by a; reach screw; Islzl. having". a beltand; socket. joint H2. by which. it. is supported: for swivel. movement;The. outer'emi hasa crank. orothersdeviceby which it can; be turnem. Theinner end has:screw-tr iread'ed engagement. with a: gimbal: ring Hmmounted in: the free: endaor the directiond'amper by means of:trimnionsibywhichi therequisite compound movement; is secured inconjunction with the joint I. l: lr--see particularly Figs. 19 and. 20.

the manuaiactureof my heating plant.- it' is a proposed: that thefurnace casing shall be interchangeable: with. that" of the stove; Thecasing may be bolted to the unitbase or frame by angle clipsasillustratedi at fil i in: Fig. 18.

From. the preceding: description it will be manitest. that I have setforth a highly eflicient and economics/l1 heating apparatus of the hotair type and. one: which is adapted for various uses and canbemodified:according to the purpose for which. it isintended.

It will. be understood that such changes and variations in constructionof" the structure" asset out in this specification may be resorted to ascome within the subjoined claims.

WhatI claim is:

In a heating apparatus of the kind, describedi a firebox; a series" ofvertical tubes at a side thereof, said tubes closed attheirends andspaced to provide intervening passages for cirulati'on of heated" air; asmoke pipe communicatingwith the upper part or the end tube oftheseries; upper and lowerhorizontal ducts forming communications betweenthe firebox and the" tubeswhereby'products of combustion may either passdirectlyto the smoke pipe or downwardly through one-tubeand upwardiythrough the next,

a horizontal damper in one 'of the upper ducts between adjacent tubes, acombined damper and deflector plate disposed in the bottom part of theend tube of the series for controlling a port provided in the bottomthereof, the combined damper and deflector plate being hingedly mountedat an edge of said port adjacent to the lower duct of the said end tubefor directing the products of combustion upwardly of said port whenopened, means for conducting foul air to said port, and a caseencompassing said series of vertical tubes and forming a wall part ofsaid passages for circulation of heated air, said case having inlet andoutlet openings.

2. In a heating apparatus of the kind described a firebox, a radiatorfor utilizing the products of combustion therefrom, said radiatorcomprising a first vertical tube and a second vertical tube at the rearof the firebox having a port in its hottorn, the tubes being closed attheir ends, a first duct forming a communication between the up- .perpart of the firebox and the upper end of the first vertical tube. asecond duct forming a communication between the upper ends of saidtubes, a third duct forming a communication between the lower ends ofsaid tubes, a damper horizontally disposed in said second duct, adeflector horizontally arranged within the bottom portion of said secondtube and disposed over said port for controlling the same and having anedge hinged adjacent to said third duct whereby it is upwardly swingableto open the port and at the same time to divert products of combustionfrom the third duct over and upwardly of the port, means for controllingsaid dampers, a smoke pipe leading oif the upper end of said secondtube, and a casing enclosing said tubes and providing a chamber forheated air having inlet and outlet openings.

3, In a heating apparatus of the kind described, a firebox, a series ofvertical tubes at a side thereof, said tubes closed at their ends andspaced to provide intervening passages for circulation of heated air, asmoke pipe communicating with the upper part of the end tube of theseries, upper and lower horizontal ducts forming communications betweenthe firebox and the tubes whereby products of combustion may either passdirectly to the smoke pipe or downwardly through one tube and upwardlythrough the next, a horizontal damper in one of the upper ducts betweenadjacent tubes, a combined damper and deflector plate disposed in thebottom part of the end tube of the series for controlling a portprovided in the bottom thereof, the combined damper and deflector platebeing hingedly mounted at an edge of said port adjacent to the lowerduct of the said end tube for directing the products of combustionupwardly of said" port when opened, a ventilator housing below said endtube of the series adapted to surround the said port and having anopening for drawing off foul air from a room.

4. A structure as set forth in claim 1, in which means are provided onsaid case to support the series of tubes in elevated position withrespect to the supporting surface of the room in which the heatingapparatus is installed, and in which a ventilator duct encloses the portin the end tube of the series and depends to said supporting surface andhas an opening at its bottom for admittance of air.

5. A structure as set forth in claim 1, in which means are provided onsaid case to support the series of tubes in elevated position withrespect to the supporting surface of the room in which the heatingapparatus is installed, and in which said means for conducting foul airto said port includes a sloping pipe extending to a register in saidsupporting surface.

6. A structure as defined in claim 2, in which a ventilator duct dependsfrom the second vertical tube and encases the inlet side of the porttherein and has an opening in a wall portion, and in which a slide platecontrols said opening and is actuated by the deflector.

'7. A structure as defined in claim 2, in which an apertured ventilatorduct depends from the second vertical tube to enclose the inlet side ofthe port therein, and in which the aperture of the ventilator iscontrolled by a slide plate connected by a tandem rod to the deflector.

8. In a heating apparatus of the kind described, a firebox, a series ofvertical tubes at a side thereof, said tubes closed at their ends andspaced to provide intervening passages for circulation of heated air, asmokepipe communicating with the upper part of the end tube of theseries,

upper and lower horizontal ducts forming communications between thefirebox and the tubes whereby products of combustion may either passdirectly to the smoke pipe or downwardly through one tube and upwardlythrough the next, a horizontal damper in one of the uper ducts betweenadjacent tubes, 2. combined damper and deflector plate disposed in thebottom part of the end tube of the series for controlling a portprovided in the bottom thereof, the combined damper and deflector platebeing hingedly mounted at an edge of said port adjacent to the lowerduct of the said end tube for directing the products of combustionupwardly of said port when opened, a mechanical connection between saiddamper and the said combined damper and deflector plate whereby in theopening movement of the combined damper and deflector plate the saiddamper is moved toward a closed position, and lost motion means wherebyeither is operable independently of the other, means for conducting foulair to said port, and a case encompassing said series of vertical tubesand forming a wall part of said passages for circulation of heated air,said case having inlet and outlet openings.

9. In a heating apparatus of the kind described, a firebox, a series ofvertical tubes at a. side thereof, said tubes closed at their ends andspaced to provide intervening passages for circulation of heated air, asmoke pipe communicating with the upper part of the end tube of theseries, upper and lower horizontal ducts lforming communications betweenthe firebox and the tubes whereby products of combustion may pass eitherdirectly to the smoke pipe or downwardly through one tube and upwardlythrough the next, a horizontal damper in one of the upper ducts betweenadjacent tubes, a combined damper and deflector plate disposed in thebottom part of the end tube of the series for controlling a portprovided in the bottom thereof, the combined damper and deflector platebeing hingedly mounted at an edge of said port adjacent to the lowerduct of the said end tube for directing the products of combustionupwardly of said port when opened, a device connecting said damper tosaid combined damper and deflector plate for translating a movement ofone to the other and including a lever and rod connection having a lostmotion means so that one may be actuated independently of the other, anda case encompassing said series of vertical tubes and forming a wallpart of said 9 passages for convection circulation of heated air, saidcase having inlet and outlet openings.

10. A heating apparatus as defined in claim 8, in which said mechanicalconnection comprises hand levers respectively carried by said damper andsaid combined damper and deflector plate, and a rod. connected to saidlevers, the connection of said rod. to one of the levers including alongitudinal series of pins for selective engagement with a hole in saidrod and spring means for retaining said engagement, the arrangementbeing operable to vary the throw of one damper relative to the other;and in which said lost motion means comprises a pin and slot connectionbetween said rod and the other of the levers such that this lever may beshifted in one direction independently of the other lever.

FAY B. GAMBLIN.

REFERENCES CITED The following references are of record in'the file ofthis patent:

UNITED STATES PATENTS Number Name Date 305,940 Lewis Sept. 30, 1884356,980 Boynton Feb. 1, 1887 580,691 Hedges Aug. 13, 1897 611,359Dickson Sept. 27, 1898 881,960 Rolin Mar. 17, 1908 1,549,893 SanfordAug. 18, 1925 1,658,971 Cook Feb. 14, 1923 2,174,347 Card Sept. 26, 19392,296,545 Tichbourne Sept. 22, 1942 2,348,569 Peters May 9, 1944 SeeleyMay 16, 1944

